Breaking a cylinder into sections in blender
There are several ways to do so. As you mentioned, if you really need to fill sections after cutting, I would suggest a tricky way:


Create a mesh that contains expected sections. Add Solidify modifier to this mesh, set Thickness to 0.00001. You can leave other options as default;
Add Boolean modifier to cylinder, set Operation to Difference, and Object to the section mesh. Then press Apply;
Delete the section mesh, Tab into cylinder object, select all elements, P>By loose parts to separate each sections apart;
If you want to recalculate their origins, just ShiftCtrlAltC > Origin to Geometry.




P.S.:
In the latest version (the coming 2.70), Boolean modifier supports ngons, which will generate better and cleaner result.